The HaCaT/THP-1 Cocultured Activation Test (COCAT) for skin sensitization: a study of intra-lab reproducibility and predictivity

Abstract

Regulation requires that skin sensitization hazard and potency of chemicals is assessed by a combination of in vitro and in chemico studies and that in vivo testing is conducted only as a last resort (EU, 2016).Given the complexity of the biological mechanisms underlying skin sensitization, it is generally recognized that a combination of mechanistically-based test methods is needed for both skin sensitization hazard assessment and potency prediction (Jowsey et al., 2006;OECD, 2014). Considerable progress has been made in the last decade regarding the development, validation, and adoption of alternative methods for skin sensitization hazard identification. In particular, a number of OECD Test Guidelines (TG) have been adopted that address the three major key events of the adverse outcome pathway (AOP) leading to skin sensitization. These are i) the covalent binding of electrophilic substances to nucleophilic centers in skin proteins as the molecular initiating event or first key event (OECD, 2019),

Skin sensitization to fragrance hydroperoxides: interplay between dendritic cells, keratinocytes and free radicals

“…CD14 + cells (buffy coats, 18–45 years) were differentiated as previously described (details of characterization of MoDC are provided in Appendix S1 and Figure S1; see Supporting Information) 19 . THP‐1 cells were cultured as previously described 20 …”

“…Normal human epidermal keratinocytes (NHEKs) (healthy donors, aged 23–51 years, passages 2–5) and HaCaT keratinocytes were cultured as previously described 20,21 and seeded (4·8 × 10 4 cells per cm 2 ).…”

Contact Allergy—Emerging Allergens and Public Health Impact

“…Moreover, they show some limitations in addressing bioavailability, metabolic activation and danger signals. Therefore, several new approaches are currently under development based on reconstructed human epidermis (RHE) models such as the SENS-IS assay based on the expression analysis of a large panel of genes relevant to the sensitisation process [348] or based on co-culture systems such as the HaCaT/THP1 CoCulture Activation Test (COCAT), taking advantage of interactions/cross-talk between keratinocytes and THP1 cells [349]. In parallel, considerable work on the development of integrated approaches to testing and assessment (IATA) aimed at the definition of integrated test strategies (ITS) has been initiated at the OECD level [350].…”

Kontaktallergien – Neu aufkommende Allergene und Auswirkungen für das Gesundheitswesen

“…Daher befinden sich derzeit mehrere neue Ansätze in der Entwicklung, die entweder auf rekonstruierten humanen Epidermismodellen (RHE) basieren, wie z. B. der SENS-IS-Assay, beruhend auf der Expressionsanalyse eines großen Panels von Genen, die für den Sensibilisierungsprozess relevant sind [348], oder auf Co-Kultur-Systemen wie dem HaCaT/THP1 CoCulture Activation Test (COCAT), der sich die Interaktionen/den Cross-Talk zwischen Keratinozyten und THP1-Zellen zunutze macht [349]. Parallel dazu wurden auf OECD-Ebene erhebliche Anstrengungen zur Entwicklung integrierter Ansätze für Tests und Assessments (IATA) eingeleitet, um letztlich integrierter Teststrategien (ITS) zu definieren [350].…”